Influence Of Preparation Temperature Research Articles

Synthesis and assessment of the Mo/MoO3/CZTS/Ag diode fabricated by one-pot hydrothermal route: impact of temperature

A facile one-step hydrothermal method was utilized to prepare Cu2ZnSnS4 film employing EDTA as a complexing agent. An effective Molybdenum oxide layer was also formed in the same approach for forming the Cu2ZnSnS4 film. The influence of preparation temperature on structural, morphology, and optical characteristics was studied. The formation of crystalline kesterite phase Cu2ZnSnS4 films with preferred orientation along the (112) plane was confirmed by X-ray diffraction and Raman spectroscopy, and it was also demonstrated that structure property changes with preparation temperatures: kesterite phase Cu2ZnSnS4 is formed at lower preparation temperatures and kesterite phase Cu2ZnSnS4 and Cu2S are formed with increasing preparation temperature. Also, Raman analysis confirmed the formation of a Molybdenum oxide layer on the Mo substrate. Field emission scanning electron microscopy revealed that surface morphology changes from leaves of trees to flake-flowers. According to UV-visible analysis, Cu2ZnSnS4 films exhibited high and wide absorbance spectra in the visible and infrared regions and a band gap between (1.67-1.9) eV. Photoluminescence analysis revealed emission peaks at (1.569, 1.55, and 1.56) eV for samples prepared at (160, 200, and 230)0C, respectively, which is very close to the band's gap of Cu2ZnSnS4. Finally, the electrical study of Mo/MoO3/CZTS/Ag junctions was performed by using current-voltage (I-V) measurement.

Spectral characterization of the impact of modifiers and different prepare temperatures on snow lotus medicinal residue-biochar and dissolved organic matter

This study involved the production of 20 biochar samples derived from secondary medicinal residues of Snow Lotus Oral Liquid, processed within the temperature range of 200–600 °C. Additionally, four medicinal residues, including dissolved organic matter (DOM), from 24 samples obtained using the shaking method, served as the primary source material. The investigation focused on two key factors: the modifier and preparation temperature. These factors were examined to elucidate the spectral characteristics and chemical properties of the pharmaceutical residues, biochar, and DOM. To analyze the alterations in the spectral attributes of biochar and medicinal residues, we employed near-infrared spectroscopy (NIR) in conjunction with Fourier-infrared one-dimensional and two-dimensional correlation spectroscopy. These findings revealed that modifiers enhanced the aromaticity of biochar, and the influence of preparation temperature on biochar was diminished. This observation indicates the stability of the aromatic functional group structure. Comparative analysis indicated that Na2CO3 had a more pronounced structural effect on biochar, which is consistent with its adsorption properties. Furthermore, we utilized the fluorescence indices from UV–visible spectroscopy and excitation-emission-matrix spectra with the PARAFAC model to elucidate the characteristics of the fluorescence components in the DOM released from the samples. The results demonstrated that the DOM released from biochar primarily originated externally. Aromaticity reduction and increased decay will enhance the ability of the biochar to bind pollutants. Those results confirmed the link between the substantial increase in the adsorption performance of the high-temperature modified charcoal in the previous study and the structural changes in the biochar. We investigated the structural changes of biochar and derivative DOM in the presence of two perturbing factors, modifier and preparation temperature. Suitable modifiers were selected. Preparation for the study of adsorption properties of snow lotus medicinal residues.

In-situ formation, structural transformation and mechanical properties Cr[sbnd]N coatings prepared by MPCVD

This study innovatively employed the microwave plasma chemical vapor deposition (MPCVD) technique to fabricate CrN coatings. The influence of preparation temperature on chemical composition, crystalline phase, morphology, and mechanical properties of the coatings were analyzed systematically. The increase of preparation temperature resulted in the structural transformation of the CrN coatings from the duplex of Cr2N/CrN to the single-phased Cr2N. The coatings with dense and flat surface were obtained at ≤800 °C; however, the decomposition of CrN to Cr2N and N2 led to the formation of pores at ≥850 °C and consequently an increase in friction coefficient and wear. The hardness and elastic modulus increased with increasing temperature because of the structural evolution of the CrN coating and phase transformation. 800 °C was the optimal preparation temperature as the coating exhibited a dense surface and possessed the best overall mechanical properties.

Influence of Preparation Temperature on the Properties and Performance of Composite PVDF-TiO2 Membranes.

Composite PVDF-TiO2 membranes are studied extensively in literature as effective anti-fouling membranes with photocatalytic properties. Yet, a full understanding of how preparation parameters affect the final membrane structure, properties and performance has not been realized. In this study, PVDF-TiO2 membranes (20 wt% TiO2/PVDF) were fabricated via the non-solvent-induced phase separation (NIPS) method with an emphasis on the preparation temperature. Then, a systematic approach was employed to study the evolution of the membrane formation process and membrane properties when the preparation temperature changed, as well as to establish a link between them. Typical asymmetric membranes with a high porosity were obtained, along with a vast improvement in the permeate flux compared to the neat PVDF membranes, but a reduction in mechanical strength was also observed. Interestingly, upon the increase in preparation temperature, a significant transition in membrane morphology was observed, notably the gradual diminution of the finger-like macrovoids. Other membrane properties such as permeability, porosity, thermal and mechanical properties, and compression behavior were also influenced accordingly. Together, the establishment of the ternary phase diagrams, the study of solvent–nonsolvent exchange rate, and the direct microscopic observation of membrane formation during phase separation, helped explain such evolution in membrane properties.

Influence of preparation temperature on ionic conductivity of titanium-defective Li1+4xTi2−x(PO4)3 NASICON-type materials

NASICON-type Li1+4xTi2−x(PO4)3 samples (0 ≤ x ≤ 0.2) have been synthesized by conventional solid-state reaction. Structural factors that affect Li conductivity were investigated with powder X-ray diffraction (XRD), scanning electron microscopy, nuclear magnetic resonance (NMR) and impedance spectroscopy techniques. The increment in lithium enhances Li–Li repulsions and increases Li conductivity of x = 0.1 samples with two orders of magnitude with respect to that of the stoichiometric x = 0 sample. In LiTi2(PO4)3 phase, Li ions mainly occupy sixfold M1 sites (CQ ~ 40 kHz), while in Li1+4xTi2−x(PO4)3 samples, Li ions are also allocated near triangular windows that connect M1 and M2 cavities (CQ ~ 60 kHz). T he Li rearrangement increases long-range motions of lithium. XRD and 31P MAS-NMR patterns showed variable amounts of secondary LiTiPO5, TiP2O7 and Li4P2O7 phases besides NASICON compounds. The formation of non-conducting secondary phases at the surface of NASICON particles decreases overall conductivity of x = 0.2 samples. The Li1.4Ti1.9(PO4)3 (x = 0.1 sample) prepared at 800 °C displays at room temperature high "bulk" conductivity, 1.6 × 10−4 S cm−1, low activation energy, 0.30 eV, and good overall DC conductivity, 2.7 × 10–6 S cm−1. The small amount of secondary phases detected in this sample makes it a good candidate for solid electrolyte in all solid-state batteries.

Influence of preparation temperature and acid treatment on the catalytic activity of MnO2

Manganese oxide is a cheap catalyst that has found wide application in environmental fields due to its excellent catalytic properties. In this work, we first prepared manganese oxides using a simple redox reaction between K2FeO4 and MnSO4, then applied the prepared MnO2 under different acid treatments (H2SO4, HNO3, HAc), and finally explored the effect of preparation temperature and acid treatment on the performance of the catalytic combustion of dimethyl ether and selective catalytic reduction of NOx with NH3 (NH3-SCR). The results show that the synthesis temperature has a great effect on the crystal phase of the product and the corresponding activity. The product fabricated at room temperature has a mixed phase of α-MnO2 and γ-MnO2, and displays superior performance in the above two catalytic reactions. After acid treatment, the catalytic activity is further improved. The catalytic performance is related to reducibility, surface oxygen species, and the acidity of the MnO2.

Influence of preparation temperature on the properties of C/ZrC composites

The preparation temperature for C/ZrC composites was optimized by assessing the effects on their mechanical and ablation properties. The composites were prepared by precursor infiltration and pyrolysis at 1500 °C, 1550 °C and 1600 °C. With rising preparation temperature, the open porosity of the composites increased, accompanied by formation of a strong interface and aggravated damage to carbon fibers, which were adverse to the mechanical properties. As a result, the flexural strength and fracture toughness decreased from 232 MPa to 11.9 MPa m1/2 to 103 MPa and 3.4 MPa m1/2 respectively. Meanwhile, elevating the open porosity provided more passage for oxygen into C/ZrC composites, which weakened the ablation resistance. The linear recession rate increased from 21.0 μm/s to 32.0 μm/s and then to 35.7 μm/s. Taking mechanical and ablation properties into consideration simultaneously, the optimum preparation temperature was 1500 °C.

Influence of preparation temperature on the oxidation resistance and mechanical properties of C/SiC coated C/C composites

A C/SiC oxidation resistance coating was prepared on carbon/carbon (C/C) composites by slurry and pack cementation. The microstructure, oxidation resistance and mechanical properties of C/SiC coating prepared from 1773 to 2573K were investigated. With the increase of the preparation temperature, the oxidation resistance of C/SiC coating increases, however, the flexure strength decreases gradually. The preparation of C/SiC coating on C/C composites results in the fracture behavior of C/C composites changing from pseudo-plastic to brittle failure model. The decrease of flexure strength is mainly attributed to the decrease of C/C matrix’ flexure strength at high temperature.

前駆体処理温度によるTiO<sub>2</sub>(B)の安定性と電気化学特性への影響

前駆体処理温度によるTiO<sub>2</sub>(B)の安定性と電気化学特性への影響

Influence of preparation temperature on morphology evolution and growth mechanism of CrB2 in Al–Cr–B alloys

The morphology evolution of CrB2 in Al–Cr–B alloy has been studied in this work. It is found that the final morphology of CrB2 is inevitably influenced by the preparation temperatures. At different preparation temperatures, the CrB2 crystals display various geometric shapes, such as hexagonal plate and hexagonal prism. The morphology transformation of CrB2 is related with the reaction paths and growth mechanisms. Besides, a growth model is proposed to understand the formation of CrB2.

Preparation of mesoporous silica replica using ordered mesoporous carbon by vapor phase transport of silica source

A new vapor phase transport (VPT) technique to prepare an inverse silica replica of an ordered mesoporous carbon was developed. Tetraethyl orthosilicate (TEOS) was infiltrated in mesoporous carbon CMK-3 as the hard template at 180 °C for 48 h under an autogenous pressure in an autoclave in the presence of water. The samples obtained by removal of CMK-3 retained structural regularity of CMK-3 with little shrinkage of framework, which were characterized by SAXRD, N2 adsorption, TG-DTA, and SEM. Influence of preparation temperature on the loading amount of silica was investigated. The multi-step replication process was monitored by characterizing the replicated materials as well as intermediate composites.

Organic conductor: Influence of preparation temperature

The conducting polypyrrole–polyethylene glycol (PPy–PEG) composite films were produced at various polymerization temperature ranging from 5 °C to 60 °C using 1 × 10 −3 M PEG, 0.20 M pyrrole and 0.10 M p-toluene sulfonate at 1.20 V (vs. SCE). The polymerization temperature of 5 °C appeared as the optimum preparation temperature showing the highest electrical conductivity of 70 S/cm and the thermal diffusivity of 8.76 × 10 −7 m 2 s −1. The electrical conductivity and thermal diffusivity exhibited a decreasing trend with the increase in polymerization temperature in the pyrrole solution used to prepare the composite films. The XRD results reveal that low temperature (5 °C) typically results in more crystalline films, which are denser, stronger and have higher conductivity. The optical microscopy of PPy–PEG shows the globular surface morphology. The surface of the of the solution side of PPy–PEG film prepared at low temperatures showed a globular morphology.

Preparation of Sm<sub>2</sub>O<sub>3</sub> Optical Thin Film by Hydrothermal Process

Sm2O3 optical thin films were prepared by hydrothermal method using samarium dichloride as source material. The influence of preparation temperature on the crystallinity, morphology and optical properties of Sm2O3 thin film were investigated. The as-fabricated thin films were characterized by X-ray diffraction, atomic force microscopy and spectrophotometer. Results show that the prepared thin film is Sm2O3 crystallites thin film with compact and uniform surface microstructures. Transmittance curve displays that the Sm2O3 crystallites thin films are transparent to visible and infrared light; and possess excellent absorbency of UV light. With the increase of deposition temperature, the crystallinity and optical properties of the prepared Sm2O3 thin film are improved. With the increase of hydrothermal temperature from 170 °C to 185 °C, the bandgap of the thin film increase from 2.88 eV to 2.95 eV.

Preparation Temperature Dependence of Size and Polydispersity of Alkylthiol Monolayer Protected Gold Clusters

The influence of preparation temperature on the size and size distribution of dodecylthiol monolayer protected gold clusters was studied. The monolayer protected clusters (MPCs) were synthesized by two different variations of the Brust-Schiffrin procedure. In all of the experiments, the stoichiometry of the reactants dodecylthiol, HAuCl(4), and sodium borohydride was kept constant, while the temperature was varied in the range of -18 to +90 degrees C. Two series were performed in which an aqueous solution of NaBH(4) was either added over 30 s or all in one portion. The size and size distribution of the MPCs were determined by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). It has been demonstrated that in general the MPC size increases with elevated preparation temperatures.

Influence of preparation technology on the microstructure and anti-oxidation property of SiC–Al2O3–mullite multi-coatings for carbon/carbon composites

Abstract Oxidation protective SiC–Al2O3–mullite multi-coatings for carbon/carbon (C/C) composites were prepared with a two-step pack cementation process. The influence of preparation temperature and SiO2/Al2O3 ratio of the pack powder on the phase, microstructure and oxidation resistance of the multi-coatings were investigated. It showed that the multi-coatings that contained mullite could be produced at 1700–1800 °C. A denser coating surface was acquired with the decrease of SiO2/Al2O3 ratio in the pack chemistries while a little damnification to the interface of the coating and C/C substrate. The as-prepared coating could effectively protect C/C composites from oxidation at 1600 °C for 81 h.

High surface area anatase titania nanoparticles prepared by MOCVD

Anatase titania nanoparticles with the average grain sizes ranging from 7.4 to 15.2 nm are prepared using pyrolysis of titanium tetrabutoxide in oxygen containing atmosphere by MOCVD method. Influence of preparation temperature on the average grain size of the particles is investigated, followed by discussion. At low preparation temperatures nucleation dominates the process while growth of the particles becomes a controlling factor at high temperatures. The as prepared anatase titania nanoparticles show a surface area as high as 180 m 2 g −1. The transformation temperature of the high surface area nanoparticles from anatase to rutile is as high as 700–1000 °C, which is about 200 °C higher than that of the particles prepared by spray hydrolysis method.

Infrared spectroscopic investigation of structure and crystallization of aluminosilicate glasses

Fourier transform infrared (FTIR) absorption spectra have been measured for a series of potassium aluminosilicate glasses. The influence of preparation temperature, atmosphere, composition and crystallization of the studied glasses on their structure is discussed. Systematic changes are observed in the frequency and intensity characteristics of the spectral bands with variations in iron content for these glasses. The 57Fe Mössbauer spectroscopy was used to find the correlation between the coordination number and the valence state of Fe 2+ and Fe 3+ cations. The phase composition of samples undergoing crystallization was confirmed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). On the basis of FTIR spectra and other considerations, a structural model is proposed to describe potassium aluminosilicate glasses containing iron oxides. It is found that the analyzed glasses have three-dimensional network structures, with silicon and aluminium in tetrahedral coordination. However, iron exhibits a variety of bonding geometries. Glass structures, intermediate between very highly ordered network forming units and crystallites regions, are also discussed.

The Influence of Preparation Temperature on the Properties and Stability of Egg Lecithin Lipsomes

The Influence of Preparation Temperature on the Properties and Stability of Egg Lecithin Lipsomes